Correct ignition switch

[Rick8814 1]

Hello all! Can any one help me with the correct switch and terminal letters? 1998 toro wheel horse 312-8. Model number 73428 serial number 8900839. I tried the switch in the parts manual. But didn't fix the issue. Won't start. Can't get the kill relay to energize, and no power to small blue wire on the solenoid. I tested the solenoid as per the electrical manual and its good. I messed up some where because when I turn the key the first 10 amp fuse blows. Any help much appreciated Rick 

[gwest_ca-(File Mod) 12,237]

This should help. Click on the picture in the link for more

Are you looking at the 5 pages of colored wiring?

 

[953 nut 66,136]

8 hours ago, Rick8814 said:

when I turn the key the first 10 amp fuse blows

Can you give us a bit of background on what led you to replacing the ignition switch?

What if anything did you do prior to changing the ignition switch that could have impacted your electrical wiring?

Is the switch you bought the one Gary has given you information on?

The drawing below shows all of the components that come into play when the key is turned to START.

I do not own this model but suspect that the Neutral Safety Switch is located on the metal plate the shift lever comes through. Examine the wiring to that switch first.

A pinched wire could be grounding out causing the fuse to blow. Check all of the wiring anyplace close to any work that has been done.

Good luck and let us know what you find.

[Rick8814 1]

Thanks guys! I got this 312-8 from a friend who was just jumping it across the solenoid. I didn't want that. So I started replacing all electric components. Still nothing. So I started researching and eliminating stuff. It comes down to the kill relay not energizing in the start circuit. New relay is good I checked it with the other relays. I bypassed all switches even though I replaced every one except the seat switch which I bypassed. Ill look at these new schematics and see if I can get a clue. Thanks so much Rick

[Rick8814 1]

Update

 Got the the three relays to energize in the start circuit. Fixed the the problem with the first 10 amp fuse from blowing. Still no power out of the blue wire at the solenoid.  You can jump it across the solenoid so I know the starter is good. Im stumped. Thanks Rick 

[953 nut 66,136]

@Rick8814, Glad you are making progress. Have you attempted using a small jumper wire to the blue wire on the solenoid to confirm it works electricley. 

Are you in the seat (or have a weight in it) of the tractor when attempting to start it? Is the Parking Brake set AND transmission in Neutral. Both seem to be insectary to have the kill relay close.

@gwest_ca, If I am not mistaken the main schematic is drawn with all switches and relays in the off the shelf position. No power to the relays and all NO switches open and NC switches closed. is that correct? Anything you could add would be appreciated.

 

[Rick8814 1]

Thank you for all the info. Thats the weird thing no power on that blue wire at the solenoid. If I jump a wire from the blue and white wire at the switch to that terminal on the solenoid it will crank. Still stumped 😆 🤣 😂 

[953 nut 66,136]

17 hours ago, Rick8814 said:

kill relay not energizing

If the kill relay is not energizing that will prevent the solenoid from closing even with power to the blue wire on the solenoid because there wouldn't be a ground path. The  K4 neutral relay need to be energized and the K3   relay has to be deenergized for the kill relay K1  to energize providing a ground path to the solenoid.

For testing purposes only, remove the small BROWN wire from the solenoid and replace it with a wire that connects to ground on the engine or frame, see if the engine will turn over with the key switch. If it will turn over you will know that the PTO switch and seat switch are good and the K3 relay is not energized.

We will get this problem resolved, just a matter of finding out what is working and what is not.

[Rick8814 1]

Thank you sir! I will do that. I did check the ground on that brown wire while it was attached and it was good. But ill check it disconnected. Does the key switch need to be grounded? Thanks Rick

[gwest_ca-(File Mod) 12,237]

@gwest_ca, If I am not mistaken the main schematic is drawn with all switches and relays in the off the shelf position. No power to the relays and all NO switches open and NC switches closed. is that correct? Anything you could add would be appreciated.

I believe you are correct on this one but not all are the same. That is why there are notes with the switches telling us the state of the switch or relay - open or closed.

Many relays did not have the common wire correct and tried to make those corrections as I found them. They had the colors right but their location was not. That is why I added a short colored wire going nowhere on the relays.

 

When the wiggly coil on a relay is energized the magnetic force created pulls the contact towards the coil breaking one circuit and energizing another. The contact pivots on the common terminal.